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The production of nanofibers of bioactive glass by laser spinning is reported. The technique yields a great quantity of free-standing fibers in the form of a mesh of disordered intertwined fibers. The method does not rely on chemical processing and does not need any chemical additive. It involves melting of a precursor material with tailored composition, which makes it possible to produce nanofibers from materials with which conventional melt drawing techniques cannot be used. Herein, the production of 45S5 Bioglass® nanofibers is reported for the first time. The process is very fast (nanofibers of several centimeters are grown in a fraction of a second), without the necessity of post heat treatments, and no devitrification was observed as a result of 2 the laser spinning process. The morphology, composition and structure of the nanofibers were characterized and their bioactivity assessment was carried out by immersion in SBF. This technique provides a method for the rapid production of dense glass nanofibers which can be employed as bioactive nanocomposite reinforcement, as a synthetic bone graft to replace missing bone, or to produce 3D structures for use as scaffolds for bone tissue engineering.

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Assist gas plays a central role in laser fusion cutting. In this work, the aerodynamic interactions between the assist gas and the workpiece are reviewed. An insight into those phenomena that hinder the cutting quality and performance is provided. These phenomena include shock waves, choking, boundary layer separation, etc. The most relevant and promising attempts to overcome these common problems related to the gas dynamics are surveyed. The review of the current scientific literature has revealed some gaps in the current knowledge of the role of the assist gas dynamics in laser cutting. The assist gas interactions have been investigated only under static conditions; and the dynamic interaction with the molten material on the cutting front has not been addressed. New nozzle designs with improved efficiency of molten material removal are required to improve cut quality; and cutting speed in current industrial laser cutting machines; especially in those assisted by new high-brightness laser sources.